Perl: Matching hash keys to a regular expression

Question

I\'m wondering if Perl has a built-in way to check for the existence of a hash element with a key matching a particular regex. For example:

my %h = ( \'twelv         


        

Answer 1

The smart match operator does this (available since Perl v5.10).

$a      $b        Type of Match Implied    Matching Code
======  =====     =====================    =============
...
Regex   Hash      hash key grep            grep /$a/, keys %$b
...

Sample usage:

# print if any key in %h ends in "teen"
print "We have some teens\n" if /.*teen$/ ~~ %h;